Process for preparation of fused pyrroles
US6872835B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jul 2, 2001 |
| Grant date | Mar 29, 2005 |
| Priority date | — |
| Expiry date | Jan 11, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D209/96
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention provides processes for the preparation of fused pyrroles, preferably indoles, which permit the use of inexpensive aromatic amines themselves as the raw material and attain high atomic efficiency and high regioselectivity. Specifically, a process for the preparation of fused pyrroles, e.g., indoles bearing methyl at the 3-position of pyrrole ring and R1 (or R2) of the general formula (4) at the 2-position thereof, or 3,3-disubstituted indoles bearing R1 and R2 at the 3-position of pyrrole ring and methyl at the 2-position thereof, characterized by reacting an alkynol of the general formula (4) with an aromatic primary amine in the presence of a ruthenium complex, more preferably with an acid or an ammonium salt thereof being made to coexist. [In the general formula (4), R1 and R2 are each independently hydrogen, optionally substituted alkyl, or optionally substituted aryl, or alternatively R1 and R2 may be united to form an alkylene chain.]
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.